Tray

ABSTRACT

A tray comprising upstanding side and end walls and a gridwork bottom. Said side and end walls are joined in the upper portions thereof so as to form substantially square corners, and are joined in the lower portions thereof so as to form curved corners.

United States Patent [191 Johnson [4 1 Sept. 16, 1975 TRAY [75] Inventor: Lewis T. Johnson, Bartlesville, Okla.

[73] Assignee: Phillips Petroleum Company,

Bartlesville, Okla.

22 Filed: Nov. 7, 1973 21 App]. No.: 413,581

[52] U.S. 220/83; 206/509; 220/72 [51] Int. B65D l/34; B65D 21/02 [58] Field of Search 220/66, 72, 74, 83;

[56] References Cited UNITED STATES PATENTS Emery 206/519 Primary Examiner-George E. Lowrance Nascher. 206/509 Frater 206/509 0/66 Fraser et al 22 ABSTRACT A tray comprising upstanding side and end walls and a gridwork bottom. Said side and end walls are joined in the upper portions thereof so as to form substantially square corners, and are oined in the lower portions thereof so as to form curved comers.

6 Claims, 7 Drawing Figures TRAY This invention relates to a tray.

Trays of various kinds have been widely employed in moving commodities,- e.g.,,foodstuffs, from one location to another. It is desirable that said trays be of a durable, rigid, light weight structure, be easy to handle in use, be easy to store when not in use, be of a simple and inexpensive construction which is easy to manufacture, and be economical in cost, regardless of size. For example, said trays should have a structure which facilitates stacking thereof when not in use, both with like trays and also unlike trays having compatible dimensions. Said trays should be easy to clean and all surfaces thereof should be self-draining. It is also desirable that said trays be resistant to collection of foreign matter, e.g., dirt, flour, etc., in any corners, angles, etc. in the tray structure. Few, if any, trays meeting all of the above requirements have been provided by the prior art.

The present invention solves the above-described problems by providing a tray which meets all of the above requirements. A feature of the trays of the invention is that all surfaces of the tray structure are selfdraining during cleaning. A further feature is that the trays are resistant to the collection of foreign matter in or on the structure thereof, e.g., at the junctions between structural members. These features are made possible by providing the tray with a structure wherein the various structural members themselves, and the intersections and other junctions between said structural members of the tray are provided with curved surfaces. Said curved surfaces are resistant to the collection of foreign matter and are self-draining during washing operations. By providing the trays of the invention with a structure wherein the side and end walls are joined in the upper portions thereof so as to form substantially square corners, and are joined in the lower portions thereof so as to form curved corners, the stacking of said trays with other trays of compatible dimensions having round or square comers is facilitated.

Thus according to the invention there is provided a tray comprising: a pair of upstanding opposed first wall members; a pair of upstanding opposed second wall members transverse to said first wall members; each of said wall members comprising an upper portion and a lower portion, with said upper portion being offset outwardly and upwardly from said lower portion; said upper portions of said first wall members being joined in a substantially square junction along the upstanding edges thereof to the upstanding edges of said upper portions of said second wall members to form an upper wall portion having substantially square corners; said lower portions of said first wall members being joined in a curved junction along the upstanding edges thereof to the upstanding edges of said lower portions of said second wall members to form a lower wall portion having curved comers; and a bottom member joined to said lower portions of said wall members to provide an open top structure.

FIG. 1 is a plan view illustrating features of the improved trays of the invention and showing a fragment of a presently preferred gridwork bottom structure in detail.

FIG. 2 is a bottom plan view of the tray illustrated in FIG. 1.

FIG. 3 is a side elevation view of the tray illustrated in FIG. 1. FIG. 4 is a cross section view taken along the line 4-4 of FIG. 1.

FIG. 5 is a cross section taken along the line 5-5 of FIG. 1.

FIG. 6 is a fragmentary plan view illustrating one gridwork bottom construction which can be employed in the trays of the invention.

FIG. 7 is a partial side elevation view showing two trays of the invention in nested relationship.

Referring now to the drawings wherein like reference numerals are employed to denote like elements, the invention will be more fully explained. In FIG. 1 there is illustrated a generally rectangular tray 10 comprising a pair of upstanding, opposed first or side wall members 12 and 12. A pair of upstanding, opposed second or end walls 14 and 14 are disposed transverse to said first walls and are joined in a junction along the upstanding edges thereof to the upstanding edges of said first wall members. A bottom member is joined to the lower portions of said first wall members and to the lower portions of said second wall members to provide an open top structure. As illustrated, said bottom member comprises a plurality of intersecting grid members, designated generally by the reference numeral 16, which are joined at the ends thereof to said wall members. Preferably, the radius of curvature at the junctions of said wall members and the radius of curvature at the junctions of said grid members with said wall members are at least one-fourth inch. While said bottom member has been illustrated as comprising a gridwork, it is within the scope of the invention for said bottom member to comprise a solid panel.

Referring now to FIGS. 3 and 5, it will be noted that each of said wall members 12, 12', 14 and 14 comprises an upper portion 18 and a lower portion 20. As illustrated in FIG. 5, said upper portion 18 is offset outwardly and upwardly from said lower portion 20. Thus, at least a part of said upper portion of each said wall member and said lower portion of each said wall member are offset from each other so as to form a curved internal shoulder on the inner walls of said wall members and a curved inverted external shoulder on the outer walls of said wall members. FIG. 5 illustrates one embodiment wherein said internal shoulder is provided with a horizontally extending inner end portion. Preferably, the upper surface of said bottom member(s) coincides with the upper surface of the inner end portion of said internal shoulder, and said internal shoulder, in effect, forms an upwardly curved junction between said bottom member(s) and the lower portions of said wall members.

As mentioned, at least a part of the upper portion of each wall member is offset outwardly in a generally vertical direction, as at 18, from the lower portion thereof to form a curved internal shoulder on the inner walls of said wall members and a curved inverted external shoulder on the outer walls of said wall members. Preferably, the radius of curvature 22 of said internal shoulder and the radius of curvature 24 of said external shoulder are at least one-fourth inch. Preferably, said internal shoulder and said external shoulder extend completely around the periphery of the tray. However, it is within the scope of the invention to omit said shoulders from large portions of said wall members. The position of said shoulders along the height of said wall members can be varied in accordance with the desired degree of nesting of the trays when stacked, and the desired ease of removing an individual tray from nesting position at the top of a stack of trays. Said shoulders are preferably located so that the walls of one tray do not jam against the walls of an adjacent tray of the nested trays. Although not shown in the drawings, the ease of removing a top tray from a stack of trays can be facilitated by providing the upper portion of the wall member with a slight taper.

As mentioned above, the upper portions of said first wall members are joined in a substantially square junction along the upstanding edges thereof to the upstanding edges of the upper portions of said second wall members to form an upper wall portion having substantially square corners. (See FIG. 1). As there shown, said corners are substantially square. However, it will be noted that the apex 26 of said substantially square corner is curved. This is a preferred construction of the tray so as to provide the self-draining features described herein. It is preferred that the radius of curvature of the apex 26 of said substantially square corners be at least one-fourth inch. Referring to FIGS. 2 and 7, it will be noted that the lower portions of said first wall members are joined in a curved junction along the upstanding edges thereof to the upstanding edges of the lower portions of said second wall members to form a lower wall portion having curved corners 28.

By thus providing the trays of the invention with an upper wall portion having substantially square corners and a lower wall portion having curved corners, said trays will stack in nested position with other trays of compatible dimensions having either round or square corners. This is advantageous when a new user of the trays of the invention wishes to start using said trays but does not wish to discard his old trays which may have a different corner structure from the trays of the invention.

Preferably, at least one inwardly extending jog 30 (see FIG. 1) is provided in said upper portion of each wall member of at least one opposing pair of said wall members, and at least one outwardly extending boss member 32 (see FIG. 2) is provided on the outer wall surface of said lower portion of each wall member of at least one opposing pair of said wall members. In the more preferred embodiments of the invention, a plurality of spaced apart inwardly extending jogs 30 is provided in said upper portion of each wall member of each opposing pair of said wall members. Similarly, a plurality of spaced-apart outwardly extending boss members 32 is provided on the outer wall surface of said lower portion of each wall member of each opposing pair of said wall members at locations corresponding to and below said jogs in said upper portions of said wall members. This positioning of said boss members 32 and said jogs 30 is advantageous when stacking the trays in nested position. In this position the outwardly extending boss member 32 in the lower portions of the tray walls register with the inner walls of the inwardly extending jogs 30 in the upper portions of the tray walls. This registration of said boss members and said jogs markedly reduces both lateral and transverse movement of the trays when stacked in nested position and provides a more stable stack. This feature of the invention is shown in FIG. 7.

In one preferred embodiment, said gridwork bottom comprises a first plurality of grid members 34 which are disposed generally parallel to said second wall members 14 and 14, are spaced apart from each other, and extend between said pair of first wall members 12 and 12. A second plurality of grid members 36 are disposed generally parallel to said first wall members 12 and 12', are spaced apart from each other, and extend between said pair of second wall members 14 and 14. Said second grid members are disposed generally parallel to said first wall members in an intersecting direction with respect to said first grid members so as to form a junction therewith and form a plurality of rectangles arranged in rows generally parallel with said wall members. Said wall members form one side of the outer rows of said rectangles. A fillet 38 is provided between each pair of adjacent grid members at said junction of said grid members. The radius of curvature of said fillet is preferably at least one-fourth inch. This structure is also illustrated in FIG. 6.

In another embodiment of the invention, said gridwork bottom member can further comprise a third plurality of grid members 40. Each one of said third grid members 40 extends substantially diagonally across one of each of said rectangles and is joined to said first and second grid members at said junction thereof to form junctions of said first, second, and third grid members. A fourth plurality of grid members 42 is also provided. Each one of said grid members 42 extends substantially diagonally across one of each of said rectangles in a direction to integrally intersect said diagonally extending grid members 40 at approximately the center of the rectangle and is joined to said first and second grid members at said junctions thereof to form junc tions of said first, second, and fourth grid members. F illets 38 are provided between each pair of adjacent grid members at all of said junctions. In each rectangle of said outer rows of rectangles there is provided a grid member 44 which extends from the intersection of said diagonally extending grid members 40 and 42 to one of said wall members. A fillet 38 is also provided at the junction of said grid member 44 with wall 12 and the intersection of said diagonally extending grid members 40 and 42.

FIG. 2 illustrates a presently preferred structure of the underside of the tray of FIG. 1. If desired each of the grid members 34, 36, 40, 42, and 44 can be pro vided with a downwardly extending rib 50 as shown in FIGS. 4 and 5 to give the grid members a generally T- shape and provide additional strength. The junction of the vertical rib 50 with the bar of the T is preferably provided with a fillet 38. Where not needed for strength, the vertical rib 50 can be omitted as shown by reference numeral 52 in FIG. 2 and the grid member will have a flat ribbon-like configuration. In FIG. 2 the vertical rib 50 has been omitted from the diagonal grid members 40 and 42 except for those of said members 40 and 42 which extend in a diagonal direction between the corners of the tray.

Said junctions of said first, second, and fourth grid members, together with said junctions of said first, second, and third grid members, form a reinforcing island. Preferably, an opening 48 is provided in said island as illustrated in FIG. 1. Preferably, the radius of curvature of the curved portions of said opening is at least onefourth inch. Said openings are preferably generally oval in shape, as illustrated. However, said opening can have a round, elliptical, or other generally curved shape.

If desired, in all the above-described embodiments of the invention, said gridwork bottom can be coved upwardly a small-distance, e.g., one-sixteenth to threesixteenths inch, from the outer edge toward the center of the tray. This will provide increased accommodation for heavier loads, i.e., without causing the bottom to sag. Preferably, as shown in FIGS. 4 and 5, the bottom portion of the grid members, e.g., 34 and 36, are curved so as to provide better self-draining properties. Preferably, the bottom portion of said wall members is also similarly curved, as also shown in said FIG. 5.

Preferably, said opposed first walls 12 and 12 slope inwardly toward each other from top to bottom, and said opposed second walls 14 and 14' slope inwardly toward each other from top to bottom. The extent to which the trays will nest one within another will be determined by the thickness and the degree of slope of said and end walls. The taper or slope of the walls should be sufficient that the trays are easily withdrawn from nested position. Usually a slope within the range of from about 2 to about from the vertical will be sufficient. While it is preferred that the trays be provided with sloping walls, it is within the scope of the invention for said walls to be disposed essentially vertical. Trays fabricated in accordance with the invention possess a number of advantageous features over trays of the prior art. The curved surfaces provided at the junctions of the various structural elements of the tray, and elsewhere, render the tray resistant to the accumulation of foreign materials such as flour, icings, jelly, etc., during use. Said curved surfaces also render the trays self-draining in essentially any position, even inverted, during washing or other cleaning operations. Said curved surfaces will have a radius of curvature sufficient to provide these advantageous features. It has been found that a radius of curvature of at least onefourth inch for said curved surfaces, while not essential in all instances, is preferred in order to insure obtaining said advantageous features. The rays of the invention are of a durable, lightweight structure. This is an important consideration in the use of said trays. For example, said trays are particularly well adapted for transporting bakery goods, both within the baking shop and the delivery truck. The bakery goods can be placed on the trays and the trays then placed in racks which may be easilypushed around the shop. The trays can also be readily loaded onto racks in a delivery truck. The light weight of the trays is a distinct advantage in that handling of the trays is not only less tiring for personnel handling same but also reduces the load on trucks.

Thus, lighter weight trucks can be employed with obvious savings in operating expenses.

The trays of the invention can be fabricated in any suitable manner known to the art. Injection molding, for example, is one presently preferred method for fabn'cating said trays. Said trays can be fabricated from any suitable material. High density polyethylenes are vespecially desirable materials from which to fabricate said trays. The high density polyethylenes prepared by the methods disclosed and claimed by J. P. Hogan et al in US Pat. No. 2,825,721, issued Mar. 4, 1958, are one group of presently preferred materials. Said trays can also be fabricated from butadiene-styrene copolymers, and other plastic materials. if desired, a reinforcing fibrous material, such as asbestos or glass fibers, can be incorporated in the plastic material. While the various plastics are presently preferred for the manufacture of the trays, it is within the scope of the invention to fabricate said trays from other materials, e.g.,

lightweight metals such as aluminum, reinforced pulp materials, etc. ,1

As an example, one model of a tray in accordance with the invention has a length of about 24 inches, a 5 width of about 22.5 inches, the rectangles formed in the gridwork bottom were about 3.25 X 3.0 inches, the top surface of the bottom grid member was about 0.25 inch wide, and the side walls were about 1.5 inch in heighLThe remainder of the elements of the tray were generally proportional in size. These dimensions are given by way of example only, are not to be construed as limiting on the invention in any way, and all can be varied within the scope of the invention.

While certain embodiments of the invention have been described for illustrative purposes, the invention is not limited thereto. Various other modifications or embodiments of the invention will be apparent to those skilled in the art in view of this disclosure. Such modifications or embodiments are within the spirit and scope of the disclosure.

I claim:

1. In a tray comprising, in combination, a pair of upstanding opposed first wall members, a pair of upstanding opposed second wall members transverse to said first wall members, each of said wall members comprising an upper portion and a lower portion with said upper portion being offset outwardly and upwardly from said lower portion, and said first wall members being joined in a curved junction along the upstanding edges thereof to the upstanding edges of said second wall members, and a bottom member joined to said lower portions of said wall members to provide an open top structure, the improvement comprising, in further 35 combination:

said upper portions of said first wall members being joined in a substantially square junction along the upstanding edges thereof to the upstanding edges of said upper portions of said second wall members to form an upper wall portion having substantially square comers; and

said lower portions of said first wall members being joined in a curved junction along the upstanding edges thereof to the upstanding edges of said lower portions of said second wall members to form a lower wall portion having curved corners.

2. A tray according to claim 1 wherein, as a further improvement, and in further combination:

at least one inwardly extending jog is provided in said upper portion of each wall member of at least one opposing pair of said wall members; and

at least one outwardly extending boss member is provided on the outer wall surface of said lower portion of each wall member of at least one opposing pair of said wall members at a location corresponding to and below said jog in said upper portion of each said wall member.

3. A tray according to claim 2 wherein, as a further improvement, and in further combination:

a plurality of spaced apart inwardly extending jogs is provided in said upper portion of each wall member of each opposing pair of said wall members; and

a plurality of spaced apart outwardly extending boss members is provided on the outer wall surface of said lower portion of each wall member of each opposing pair of said wall members at locations corre- 5. A tray according to claim 4 wherein, as a further improvement, and in further combination the upper surface of said bottom member coincides with the upper surface of said inner end portion of said internal shoulder.

6. A tray according to claim 5 wherein said bottom member comprises a plurality of intersecting grid members joined at the ends thereof to said lower portions of said wall members and to said inner end portion of said internal shoulder. 

1. In a tray comprising, in combination, a pair of upstanding opposed first wall members, a pair of upstanding opposed second wall members transverse to said first wall members, each of said wall members comprising an upper portion and a lower portion with said upper portion being offset outwardly and upwardly from said lower portion, and said first wall members being joined in a curved junction along the upstanding edges thereof to the upstanding edges of said second wall members, and a bottom member joined to said lower portions of said wall members to provide an open top structure, The improvement comprising, in further combination: said upper portions of said first wall members being joined in a substantially square junction along the upstanding edges thereof to the upstanding edges of said upper portions of said second wall members to form an upper wall portion having substantially square corners; and said lower portions of said first wall members being joined in a curved junction along the upstanding edges thereof to the upstanding edges of said lower portions of said second wall members to form a lower wall portion having curved corners.
 2. A tray according to claim 1 wherein, as a further improvement, and in further combination: at least one inwardly extending jog is provided in said upper portion of each wall member of at least one opposing pair of said wall members; and at least one outwardly extending boss member is provided on the outer wall surface of said lower portion of each wall member of at least one opposing pair of said wall members at a location corresponding to and below said jog in said upper portion of each said wall member.
 3. A tray according to claim 2 wherein, as a further improvement, and in further combination: a plurality of spaced apart inwardly extending jogs is provided in said upper portion of each wall member of each opposing pair of said wall members; and a plurality of spaced apart outwardly extending boss members is provided on the outer wall surface of said lower portion of each wall member of each opposing pair of said wall members at locations corresponding to and below said jogs in said upper portion of said wall members.
 4. A tray according to claim 3 wherein, as a further improvement, and in further combination: said upper portion of each said wall member is offset outwardly and upwardly from said lower portion thereof to form a curved internal shoulder on the inner walls of said wall members and a curved inverted external shoulder on the outer walls of said wall members, with said internal shoulder having a horizontally extending inner end portion.
 5. A tray according to claim 4 wherein, as a further improvement, and in further combination the upper surface of said bottom member coincides with the upper surface of said inner end portion of said internal shoulder.
 6. A tray according to claim 5 wherein said bottom member comprises a plurality of intersecting grid members joined at the ends thereof to said lower portions of said wall members and to said inner end portion of said internal shoulder. 